U.S. patent number 5,729,332 [Application Number 08/439,397] was granted by the patent office on 1998-03-17 for depth image printing method on precoated lenticular material.
This patent grant is currently assigned to Eastman Kodak Company. Invention is credited to Sergei V. Fogel, Roy Y. Taylor.
United States Patent |
5,729,332 |
Fogel , et al. |
March 17, 1998 |
Depth image printing method on precoated lenticular material
Abstract
A method and apparatus for printing lenticular pictures includes
imposing lines of information in the form of segmented images of a
scene onto a light sensitive material. Alternate segments or lines
are provided from different perspective views of the same scene to
be printed. The light sensitive material has a transparent
lenticular material attached thereto. The light sensitive material
is exposed, from the side opposite the lenticular material, by
light from an illuminated image. The exposure may be effected by
optical projection or by contact printing or by CRT image
projection or other device. A reference grid, having a pitch
slightly different from the pitch of the lenticular material, is
positioned on the lenticular material and is effective to cause a
Moire pattern to become visible when the lenticular material is
moved relative to the light sensitive material. The Moire pattern
is used to adjust the position of the lenticular material or the
negative, prior to exposure of the light sensitive material. After
exposure, a reflective material is applied to the side of the light
sensitive material opposite the side to which the lenticular
material is attached, to provide a three dimensional print. In
another example, several reference grids are used for additional
accuracy of alignment.
Inventors: |
Fogel; Sergei V. (Rochester,
NY), Taylor; Roy Y. (Scottsville, NY) |
Assignee: |
Eastman Kodak Company
(Rochester, NY)
|
Family
ID: |
23744553 |
Appl.
No.: |
08/439,397 |
Filed: |
May 11, 1995 |
Current U.S.
Class: |
355/77;
355/22 |
Current CPC
Class: |
G02B
30/27 (20200101); G03B 27/32 (20130101); G03B
35/14 (20130101); G03C 9/02 (20130101) |
Current International
Class: |
G03C
9/02 (20060101); G03C 9/00 (20060101); G03B
35/14 (20060101); G03B 35/00 (20060101); G02B
27/22 (20060101); G03B 027/32 (); G03B
035/14 () |
Field of
Search: |
;355/22,77
;354/112,115 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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520 179 |
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Dec 1992 |
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EP |
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560 180 |
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Sep 1993 |
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EP |
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569 896 |
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Nov 1993 |
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EP |
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570 807 |
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Nov 1993 |
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EP |
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5-088311 |
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Aug 1993 |
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JP |
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492 186 |
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Sep 1938 |
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GB |
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Primary Examiner: Braun; Fred L.
Attorney, Agent or Firm: Wilder; Robert V.
Claims
We claim:
1. A method of producing a photographic print from a negative, said
method comprising the steps of:
(a) affixing a lenticular material to a light sensitive
material;
(b) aligning the light sensitive material on an exposure plane:
said step of aligning includes the step of providing an optically
transmittable reference grid on the lenticular side of the
lenticular material, and aligning said reference grid to a fixed
reference located at a measuring position relative to the exposure
plane; and
(c) effecting the exposure of the light sensitive material from the
side of the light sensitive material opposite the lenticular
material, by light from the negative.
2. The invention as set forth in claim 1 and further including the
step, following step (c), of:
(d) affixing a reflective layer to the exposed side of said light
sensitive material, after said light sensitive film has been
exposed, said reflective layer being operable to reflect light back
through the lenticular material.
3. The invention as set forth in claim 2 wherein the reflective
layer is produced by applying a reflective coating to said light
sensitive material.
4. The invention as set forth in claim 2 wherein the reflecting
layer is produced by applying a laminate to said light sensitive
material.
5. The invention as set forth in claim 1 wherein the negative and
light sensitive material are arranged in contact to effect said
exposure through contact printing upon the light sensitive
material.
6. The invention as set forth in claim 1 wherein the negative is
displaced from the light sensitive material and light is optically
projected through the negative to the light sensitive material to
effect said exposure.
7. The invention as set forth in claim 1 wherein said lenticular
material is comprised of a plurality of juxtaposed lenticules
having a first pitch, said reference grid further including a
series of parallel lines having a second pitch between said lines,
said second pitch being different from said first pitch such that a
Moire fringe pattern is produced, the Moire fringe pattern being
utilized to determine the relative positions between said
lenticular material and the negative.
8. The invention as set forth in claim 1 wherein the lenticular
material includes a planar side placed next to the light sensitive
material and a lenticular side, and said step of aligning includes
the step of providing at least two reference grids at positions
displaced along the direction of the axes of the lenticules of the
lenticular material.
9. The invention as set forth in claim 8 and further including the
step of comparing the positions of fringes appearing at a
predetermined fixed reference location.
10. The invention as set forth in claim 1 wherein the negative
includes at least one negative reference indicium outside of the
image to be viewed, said negative reference indicium being
effective to produce a corresponding print reference indicium on
said light sensitive material, said invention further including the
step of utilizing said print reference indicium to adjust the
position of the light sensitive material.
11. A method of producing a photographic print from an illuminated
image, said method comprising the steps of:
(a) positioning a light sensitive material on an exposure
plane;
(b) aligning a lenticular material over the light sensitive
material, said step of aligning includes the step of providing an
optically transmittable reference grid on the lenticular side of
the lenticular material, and aligning said reference grid to a
fixed reference located at a measuring position relative to the
exposure plane; and
(c) effecting the exposure of the light sensitive material from the
side of the light sensitive material opposite the lenticular
material, by light from the illuminated image.
12. The invention as set forth in claim 11 and further including
the step, following step (c), of (d) affixing a reflective layer to
the exposed side of said light sensitive material to reflect light
back through the lenticular material.
13. The invention as set forth in claim 12 wherein the reflective
layer is produced by applying a reflective coating to said light
sensitive material.
14. The invention as set forth in claim 12 wherein the reflecting
layer is produced by applying a laminate to said light sensitive
material.
15. The invention as set forth in claim 11 wherein said reference
grid is arranged to be brought into contact with the lenticular
side of said lenticular material so that a Moire fringe pattern is
produced, the Moire fringe pattern being compared to said fixed
reference to determine the relative positions between said
lenticular material and the negative.
16. The invention as set forth in claim 11 wherein the lenticular
material includes a planer side placed next to the light sensitive
material and a lenticular side, and said step of aligning includes
the step of providing at least two reference grids at positions
displaced along the direction of the axes of the lenticules of the
lenticular material.
17. The invention as set forth in claim 16 and further including
the step of comparing the positions of fringes appearing at a
predetermined fixed reference location.
18. The invention as set forth in claim 11 wherein said illuminated
image is produced on the screen of a CRT, and said step of
positioning is accomplished through electronically changing the
illuminated image on said CRT.
Description
FIELD OF THE INVENTION
The present invention relates generally to image reproduction and
more particularly to an improved method and system for producing
three-dimensional pictures.
BACKGROUND OF THE INVENTION
There are two general methods of recording lenticular sheet
three-dimensional pictures, viz, continuous methods and
discontinuous methods. In a continuous method, the lenticular sheet
with a photosensitive image layer affixed or clamped to the back
surface is placed in a camera used to capture the image. In taking
a three-dimensional picture, images of the object observed from
various directions are recorded directly and continuously on the
photographic plate. In a discontinuous method, a series of planar
images representing different perspective views of a scene are
obtained first, and they are synthesized by using a special
printing device to give a lenticular picture.
The present invention pertains to printing lenticular prints using
a discontinuous method. Previous discontinuous methods of printing
lenticular prints from input images can be further classified into
two categories, namely segmented printing and composite printing.
In segmented printing, the lenticular material is utilized as an
image-forming element in the exposure process. If there are
separate views to be printed to comprise the lenticular print, each
view is recorded on a separate negative which is placed in the
negative gate of an enlarger. These multiple views could have been
simultaneously exposed by a multi-lens camera such as the 3D Magic
camera made by Image Technology of Norcross, Ga., which has three
views, or by a single camera which is traversed in front of the
scene between exposures. The enlarger is focused on a print gate
with a lateral shift of the negative gate and enlarger lens
establishing an angle of exposure correlated to the original
angular parallax used in the camera optics.
In composite printing, the information from the various views is
combined into a composite print file which is printed directly onto
the emulsion by an auxiliary optical system without reliance on the
lenticular face plate to focus the information. An example of this
is the Kodak Depth Imaging system which uses a Kodak LVT Film
Recorder to print individual lines of information sampled from the
different perspective views that could come from a camera such as
the 3D Magic or from computer-generated or computer-altered images.
This latter system produces a higher quality image, because the
focus degradation associated with the lenticular face plate does
not spread the information between adjacent views during the
printing process, and color control can easily be incorporated in
the printer exposure mechanism using lookup tables.
After exposure and developing, the printed lines are carefully
aligned with respect to the lenticular axis' orientation and the
image is laminated to the back side of the lenticular face plate.
This alignment procedure is facilitated by observing the Moire
patterns generated between the printed image and the lenticular
sheet while shifting or rotating the print. These patterns greatly
magnify the errors of very small displacements.
A segmented method of printing electronic images was previously
disclosed in U.S. patent application Ser. No. 07/974,441, filed
Nov. 12, 1992, entitled "CRT Printer for Lenticular Photographs".
In that disclosure, the negative gate of the segmented method
described earlier is replaced by a CRT screen which sequentially
displays images of the multiple views. The CRT and the enlarger
lens is similarly translated laterally after each view is projected
on the print gate surface to establish an angle of exposure
correlated to the original angular parallax used in the camera
optics. However, this method still is subject to lenticular image
spreading between adjacent views for the same reason as discussed
earlier.
A distinct advantage of the segmented method can be realized,
however, if the images are projected directly onto photosensitive
emulsion which was coated on the back surface of the lenticular
face plate prior to exposure. In this case the need for
post-alignment and lamination of the printed image to the
lenticular material is eliminated. Alignment is maintained by the
angular geometry relationship between the enlarger optics and the
printer gate which locates the lenticular optical surfaces.
The present invention combines the effects of composite printing
image quality by directly printing the recorded image lines of
information with the reduced post exposure handling of precoated
lenticular material.
The present invention is also applicable if the lenticular face
plate is laminated to conventional coated film prior to exposure
when positioning is not critical. In this procedure, the film
emulsion would be oriented to face away from the composite, and the
lenticular face plate would be made thinner by an optical thickness
equivalent to the optical thickness of the film base so that the
lenticules would properly project the information for viewing.
The present invention describes a means for making exposures of
depth image information on precoated lenticular material without
reliance on using the lenticular material in the exposure chain.
Therefore, the fidelity of the images will be improved with less
crosstalk between adjacent recorded lines of image information and
special effects such as animation or image changes will be more
distinct.
The segmented printing method is generally used for mass consumer
lenticular prints which are illuminated by ambient light in the
viewing environment. This type of print is called a reflection
print. Pre-coated lenticular material is generally manufactured for
reflection print applications by including a titanium dioxide layer
added behind the photographic emulsion on the backside to provide a
high reflectance of diffuse light reaching it through the
lenticular face plate in the viewing mode. If this titanium dioxide
layer is omitted from the initial coating procedure, it can be
either added later after image exposure, or reflectance achieved by
some other means such as laminating or otherwise affixing a
reflective material to the emulsion surface after exposure and
developing, leaving the photographic emulsion remains optically
recordable from the backside of the material. It is proposed to
expose this emulsion from this side rather than through the
lenticular side to avoid the degradation of focus discussed
earlier.
The means of exposing the emulsion could be either direct contact
printing from a negative made on a line recorder such as the LVT
Film Recorder or by optical projection with some magnification
compensation from such a negative. It would also be possible to
project an image from a CRT screen as with conventional CRT
printing which would allow some electronic manipulation of image
location and rotation.
It is important that the lines of information be printed parallel
to the lenticular axes and properly positioned with respect to
their midpoints. It is therefore proposed to position a separate
reference grid on the lenticular side of the coated material with a
spatial pitch slightly different than the lenticular pitch so that
a Moire pattern of fringes becomes visible. This fringe pattern
will greatly magnify any displacement or angular change in the
position of the lenticular material from image to image and provide
a feedback mechanism for repositioning the coated lenticular or the
negative image prior to exposure. For setup purposes, a second
reference grid can be temporarily placed in the negative gate or a
reference grid printed on the negative at some place to the side of
the final print format thereby allowing it to be trimmed away from
the image after developing.
SUMMARY OF THE INVENTION
In one embodiment of the present invention, there is provided a
method and apparatus for producing a photographic print from an
illuminated image comprising the steps of affixing a lenticular
material over light sensitive material, positioning the light
sensitive material on an exposure plane, and effecting the exposure
of the light sensitive material from the side of the light
sensitive material opposite the lenticular material, by light from
the illuminated image.
In another embodiment, the invention further includes the step of
affixing a reflective layer to the exposed side of said light
sensitive material, after exposure and development, to reflect
light back through the lenticular material.
In yet another embodiment, a reference grid is arranged to be
brought into contact with the lenticular side of said lenticular
material so that a Moire fringe pattern is produced, the Moire
fringe pattern being compared to said fixed reference to determine
the relative positions between said lenticular material and an
illuminated image or negative.
The present invention will be better understood when taken in
conjunction with the following description and drawings wherein
like characters indicate like parts and which drawings form a part
of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a prior art segmented method of exposing the emulsion
coating through the lenticular face plate;
FIG. 2 shows a prior art composite method of exposing the emulsion
with a film recorder;
FIG. 3 shows the proposed method of exposing the emulsion from the
back side by contact printing using a composite negative;
FIG. 4 shows the proposed method of exposing the emulsion from the
back side by projection from a composite negative;
FIG. 5 shows a method of adjusting a projected image for rotation
and lateral position to coincide with the orientation of the
lenticular material for small errors; and
FIG. 6 shows a perspective view of the lenticular material and
related Moire pattern.
DETAILED DESCRIPTION OF THE DRAWINGS
With more specific reference to FIG. 1, there is shown a prior art
technique of printing three-dimensional lenticular pictures on
precoated lenticular material. A translatable film gate 100 is
moved along a path including first, second and third positions,
111, 112 and 113, respectively. The film gate path is parallel to
the plane of the precoated lenticular receiver material 104 and a
projection lens 101 is moved along a mutually parallel path 108,
including corresponding first, second and third locations 131, 132
and 133, respectively. At each location, an image of a negative
placed in the film gate is focused onto the photosensitive layer
105 of the precoated lenticular receiver material 104 at a
magnification which enlarges the negative area to match the print
area. Lenticule 107 is shown for reference at the center of the
print, but the principle herein described works for all lenticules
in print. As the lens 101 is moved from position 131 successively
to position 132 and eventually position 133, the film gate 100
follows in corresponding locations 111, 112, and 113 which
maintains a coincidence of centerpoint of the film gate with
optical projection paths 121, 122, and 123.
To avoid gaps of unexposed receiver material between positions 131,
132 and 133, the exposing aperture of the lens 101 along path 108
should just touch the adjacent aperture. Since physical lens
apertures are typically not that large, a common technique is to
traverse the lens and negative with the existing aperture held open
until midway points between positions 131 and 132, and 132 and 133
have been reached, at which time, the negative is changed.
This motion can be achieved by a variety of means such as linkages,
cam devices, stepper motors, or combinations thereof. Coincident
with this motion, the actual negative present in the film gate is
also changed, since the negatives represent differing perspective
views taken at proportionally similar angles to the angles that
paths 121, 122, and 123 respectively have relative to a
perpendicular to the receiver material 104. These differing
perspective view negatives can be provided by a movable camera on a
rail or multi-lens camera such as the Nimslo camera. The quality of
the image is directly affected if the alignments of: the negative
within the film gate; the film to the lens; or, the lens to the
lenticular; change due to machine inaccuracies or wear.
If multiple images of a given subject are desired, this elaborate
printing technique must be repeated, and subsequent images become
degraded as the negative wears because of the negative transfer
mechanism. The number of different perspective views printed is
shown FIG. 1 is three, but any number from one to n can be printed
by this technique.
FIG. 2 shows a prior art method of exposing a photosensitive
emulsion with a film recorder for later alignment and lamination. A
film recorder such as the Kodak LVT Model 1620B is designed to
affix a sheet of film 201 to the outside of cylindrical drum 202.
The drum 202 is caused to rotated about its axis 203. A beam of
exposing light is focused on the emulsion of a film sheet 201 using
a microscope objective optic 204, and the exposing optical head 209
containing the optic 204 is transported along a path 205 which is
parallel to axis 203 and the film surface. The amount of the
exposing optics motion per revolution of drum 202 is made equal to
the focused spot size on the film surface. This can be carefully
maintained by changing the aperture size and shape of the beam.
As the drum rotates to new unexposed film areas, the light entering
the exposing optical head 209 is modulated for color content and
intensity with values corresponding to image content. Since the
time rate of image modulation, the time rate of rotation and the
time rate of exposing optics translation are maintained at constant
values, the resultant areas of exposure to modulation profiles are
substantially the same, and commonly referred to as pixels, or
picture elements. The progress of pixel information with respect to
image content per revolution is rapid, since with only one
revolution a whole line has been exposed, and this is called the
fast scan direction. The progress of pixel information with respect
to image content along the exposing optics translation path 205 is
slower, since each revolution of the drum only permits a
translation displacement equal to the focused spot size, and this
is called the slow scan direction.
The data providing the changing modulation control signals are
provided by a control computer not shown, but a composite print
file containing interleaved scan data from negatives provided can
be suitably used to adjacent fast scan lines which correspond to
the imaged lines from the optical paths 121, 122, 123 in FIG. 1.
The film sheet 201 can be developed, shown as process 210, to
become film sheet 227 and aligned and laminated to a lenticular
screen 228 of suitable lenticular spacing and thickness to
accomplish the same final viewing projection task as faceplate 104
does. There can also be a laborious chain of events to produce a
final depth image and the final quality subject to the accuracy of
aligning and lamination. It has also been demonstrated in prior art
that the film sheet 201 can be comprised of negative material and
that an additional contact printing operation can be inserted after
developing 210 to provide contact print copies 227 for final
assembly. The quality of image produced by this process is better
than that illustrated in FIG. 1, because of the effects of the
lenticular sheet as an optical imager are excluded.
FIG. 3 shows the proposed method of exposing the emulsion from the
back side by contact-copying a composite negative and subsequest
alignment of the receiver material for exposing. A referenced grid
301 composed of black lines and clear spaces is provided which has
the same spatial pitch as the lenticules on the precoated
lenticular receiver material 304. A negative produced on a film
recorder as described for FIG. 2 will have multiple lines per
lenticule. The relative location and rotation of the negative 302
to the reference grid 301 can be benchmarked by observing the Moire
patterns set up between the lines of the reference grid 301 and the
lines on the negative 302 when the two components are translated to
contact each other along paths 307 and 303 respectively. Paths 307
and 303 are made parallel by machine design and fixturing. Prior to
exposing the lenticular receiver material 304, comprised of
lenticular sheet 306 and photosensitive layer 305, the receiver
material 304 can be aligned for position and angle to the grid 301
by bringing grid 301 in contact with sheet 306 along path 307 and
adjusting until the same Moire pattern as previously benchmarked
has been achieved. Then the negative 302 can be translated along
path 303 to contact the photosensitive layer 305 and an exposure
made by illuminating negative 302 from the bottom side, with the
assurance that the exposed lines on the negative 302 will be
aligned to the lenticules of sheet 306. FIG. 6 shows the rotational
motion 'e' is best measured by placing pieces of the reference grid
301 at opposite ends of the lenticular print. These areas could be
located just outside the actual print area in a border. That would
allow monitoring and adjusting the alignment and rotation for each
print on a continuous web of precoated lenticular receiver material
306 extending in the direction of the lenticules.
FIG. 4 shows the proposed method of exposing the emulsion from the
back side by optical projection from a composite negative. The
reference grid 401 which can be moved to a contact position with
precoated lenticular receiver material 404 along path 407 can
similarly be used as in the contact process described in FIG. 3 to
pre-align a negative 402 similarly consisting of multiple lines per
lenticule. As an additional aid to observing the Moire &
pattern, a grid pattern 409 can be printed on the negative outside
the image area. A printer lens 403 is used to project the negative
image onto the photosensitive emulsion layer 405. Prior to
inserting the material 404 into the printing gate established by
datums or markers 410 and 411, the reference grid 401 is moved to
datum 410 and the Moire pattern between it and the image of the
grid pattern 409 benchmarked as described earlier. The material 404
can now be inserted in the printing gate between the markers 410
and 411, and a similar Moire pattern achieved by adjusting the
position of the material 404 for position and rotation. The light
source 408 can now be turned on and the image of the negative will
be printed on the layer 405.
FIG. 5 shows a preferred embodiment of the projection method
described in FIG. 4 for a printer designed to print multiple images
on a web of precoated lenticular receiver material 504. This entire
apparatus is inverted from the orientation shown in FIG. 4 for the
sake of drawing clarity, but the final orientation would be chosen
for machine design efficiency. Lens 503 provides an image 506 of
the negative 502 on layer 505. Reference grids 500 and 501 are
positioned to extend beneath the receiver material 504. The grids
500 and 501 can be provided to pre-align the rotation 'e' of
negative 502 as described for FIG. 4.
The Moire pattern is benchmarked by observing the patterns with
video cameras, the lenses 510 and 511 of which, are shown below the
web 504. Since lateral movement of web 504 may be difficult, the
image 506 of the negative 502 can be laterally shifted by using a
dithering prism 512 comprised of a small wedge angle between two
flat surfaces on a disk of glass. As the prism 512 is rotated, the
image will deviate slightly in a direction perpendicular to the
wedge surface intersection line. Therefore, the amount of lateral
shift of the image can be changed by rotating prism 512.
The method and apparatus of the present invention has been
described in connection with the preferred embodiment as disclosed
herein. Although an embodiment of the present invention has been
shown and described in detail herein, along with certain variants
thereof, many other varied embodiments that incorporate the
teachings of the invention may be easily constructed by those
skilled in the art. Accordingly, the present invention is not
intended to be limited to the specific form set forth herein, but
on the contrary, it is intended to cover such alternatives,
modifications, and equivalents, as can be reasonably included
within the spirit and scope of the invention as defined by the
claims.
PARTS LIST
100 film gate
101 lens
104 precoated lenticular receiver material
105 photosensitive layer
107 lenticule
108 path
111 location or position
112 location or position
113 location or position
121 path
122 path
123 path
131 position or location
132 position or location
133 position or location
201 film
202 drum
203 axis
204 objective optic
205 path
209 optical head
210 developing step
227 print copies
228 lenticular screen
301 grid
302 negative
303 path
304 receiver material
305 photosensitive layer
306 sheet
307 path
401 grid
402 negative
403 lens
404 receiver material
405 layer
407 path
408 light source
409 grid pattern
410 datum or marker
411 datum or marker
500 grid
501 grid
502 negative
503 lens
504 web
505 layer
510 lens
511 lens
512 prism
* * * * *